Release of fission products from the KNK II fuel element failure and search for released fuel in the primary sodium
Description
A first fuel element cladding failure occurred in the KNK II reactor on April 1st, 1979. The activity concentrations of radio nuclides are reported from four sodium samplings: the last sampling before the fuel failure, two samplings with the failed element in the core and one sampling after removal of the failed fuel element. Only I-131, Cs-136 and Cs-137 were released from the failed fuel into the primary sodium. The release fraction of Cs-137 was 5.2 % of a fuel rod inventory. The specific activities of some radio nuclides (Zn-65, Ag-110m, Sb-124,...) in the primary coolant were determined by neutron activation analysis. In addition, efforts were made to find non-radioactive cesium and released fuel in the sodium. The applied procedure is described in detail. Neither in the recent samples nor in Na stock samples from the time before nuclear operation of the plant any cesium or fuel was detected. From detection limits it was concluded, that the Cs content in the 21 metric tons of primary sodium was smaller than 10 mg and the content of fuel smaller than 1.1 mg
Availability note (English)
Available from INIS in electronic formAbstract (German)
Am 1. April 1979 trat in der KNK II ein erster Brennstab-Huellrohrschaden auf. Die Aktivitaetskonzentrationen der gemessenen Radionuklide im Primaernatrium vor dem BE-Schaden, in zwei Probenahmen mit dem schadhaften BE im Kernverband und in der ersten Probenahme nach der Entnahme des defekten Testelements aus dem Reaktor werden mitgeteilt. Nach dem Schaden wurden als Spaltprodukte im Natrium lediglich I-131, Cs-136 und Cs-137 gemessen. Der maximal freigesetzte Anteil Cs-137 betrug 5.2 % eines Stabinventars. Mit Neutronen-Aktivierungs-Analyse wurden die spezifischen Aktivitaeten einiger Radionuklide (Zn-65, Ag-110m, Sb-124,...) bestimmt. Dabei wurde auch versucht, inaktives Caesium und ausgetragenen Brennstoff im Primaernatrium nachzuweisen. Das angewandte Verfahren wird detailliert beschrieben. Weder in den Proben nach dem BE-Schaden noch in den Archiv-Proben aus der Zeit vor dem nuklearen Betrieb der Anlage konnte Caesium oder Brennstoff nachgewiesen werden. Aus den Nachweisgrenzen wurde geschlossen, dass in den 21 t Primaernatrium nur weniger als 10 mg Cs und nur weniger als 1.1 mg Brennstoff enthalten sein koennen
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Additional details
Additional titles
- Original title (German)
- Freisetzung von Spaltprodukten aus dem KNK II-Brennelementschaden und aktivierungsanalytische Suche nach ausgetragenem Brennstoff im Primaernatrium
Publishing Information
- Imprint Pagination
- 42 p.
- Report number
- KFK-PSB--01.02.17P24B
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 34086281
- Subject category
- S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS;
- Descriptors DEI
- AFTER-HEAT REMOVAL; ANTIMONY 124; CESIUM 136; CESIUM 137; DEFECTS; DELAYED NEUTRON ANALYSIS; FISSION PRODUCT RELEASE; FUEL ELEMENT FAILURE; IODINE 131; KNK REACTOR; KNK-2 REACTOR; NEUTRON ACTIVATION ANALYSIS; NEUTRON DETECTION; PRIMARY COOLANT CIRCUITS; SILVER 110; SODIUM; TESTING; ZINC 65
- Descriptors DEC
- ACTIVATION ANALYSIS; ALKALI METALS; ANTIMONY ISOTOPES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BETA-PLUS DECAY RADIOISOTOPES; CESIUM ISOTOPES; CHEMICAL ANALYSIS; COOLING SYSTEMS; DAYS LIVING RADIOISOTOPES; DETECTION; ELECTRON CAPTURE RADIOISOTOPES; ELEMENTS; ENERGY SYSTEMS; ENRICHED URANIUM REACTORS; EPITHERMAL REACTORS; EVEN-ODD NUCLEI; EXPERIMENTAL REACTORS; FAILURES; FAST REACTORS; HYDRIDE MODERATED REACTORS; INTERMEDIATE MASS NUCLEI; INTERNAL CONVERSION RADIOISOTOPES; IODINE ISOTOPES; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; LIQUID METAL COOLED REACTORS; METALS; MINUTES LIVING RADIOISOTOPES; NONDESTRUCTIVE ANALYSIS; NUCLEAR REACTION ANALYSIS; NUCLEI; ODD-EVEN NUCLEI; ODD-ODD NUCLEI; POWER REACTORS; RADIATION DETECTION; RADIOISOTOPES; REACTOR COMPONENTS; REACTOR COOLING SYSTEMS; REACTORS; REMOVAL; RESEARCH AND TEST REACTORS; SECONDS LIVING RADIOISOTOPES; SILVER ISOTOPES; SODIUM COOLED REACTORS; SZR TYPE REACTORS; THERMAL REACTORS; YEARS LIVING RADIOISOTOPES; ZINC ISOTOPES
Optional Information
- Notes
- refs, figs, tabs
- Secondary number(s)
- INIS-DE-PSB--021